Mountain Snowfall — one ECMWF run downscaled onto the real terrain

What this is. One ECMWF IFS run (0.1°, about 9 km underneath) put on the real terrain with Forecast Flakes' downscaler. Where the water falls follows PRISM's 1991–2020 normals inside the half-degree footprint the model actually resolves, and each footprint keeps the model's own total — the terrain moves water, it never adds any, so a model that is too dry in the mountains stays too dry. Whether it is snow is decided from the wet-bulb profile at each 2.5 km cell's real height, and how deep it piles from the Kuchera ratio of the column above that height. Below 2.5 km, each cell carries a curve of snowfall against elevation, read at the lift terminals for the table and at ~60 m terrain for the boxes over the big ranges. The ratio is climatological: a storm from an unusual direction loads the slope the average storm loads. This is a forecast, not a warning — for those, the National Weather Service.